Griddles are one of the major cooking appliances in commercial kitchens, particularly in a majority of the fast food and full service chain restaurants. The prior art griddles are either gas or electric powered and typically have one heating element, one thermocouple and one thermostat per linear foot thus permitting wide temperature variations between heating elements. Literally power is pushed into the food.
The problems with the prior art griddles are numerous. Such griddles typically have a 70.degree. F. temperature variation across their surfaces, they cannot deliver power to specific incremental areas, thus cold areas may call for heat and hot areas as a result are overheated or vice versa. The heat-up time from turn-on is typically 20 minutes and the griddles have a slow response time to changes in temperatures caused by change of load. Such griddles are difficult to clean; the relatively large surface areas cannot be removed for cleaning. And further, the conventional griddle does not provide cooking temperatures within three inches of its periphery.
There are also prior art consumer oriented induction cooking stoves with special pots. The pots have ferromagnetic bottoms and the stove has induction coils. These devices have coils that do not provide uniform temperature across the bottom of the pot or pan and provide minimum shielding of R.F. radiation. These coils are not designed for use in plate technology or large size pots.
Such a device is found in French Patent No. 2,527,916. This patent discloses a pot or pan with a ferromagnetic bottom. Several pots are provided each with a ferromagnetic bottom of different Curie temperatures whereby different cooking temperatures are provided.